An operator of a viewing device may desire to adjust a line of sight while observing a scene through the viewing device. Targets at very long ranges may require high levels of magnification from a weapon sight. However, the bullet drop for a target at long range may be large enough to cause the target to be outside the field of view of the weapon sight at that high magnification. Some viewing devices may be manually adjusted so as to apply a specific angle of deviation to the image as viewed by the operator. For example, the impact point of a projectile as viewed by a day scope may be adjusted in angle so that it appears to be at a point designated by the day scope's reticle. The amount of adjustment changes when the day scope is used at different target ranges.